The present invention relates to amphoteric surface active agents, and more particularly to amphoteric derivatives of aliphatic triamines, such as diethylenetriamine and Bis (hexamethylene) triamine reacted with long chain fatty acids, esters or triglycerides. In addition to being novel materials, the amphoteric derivatives of this invention are useful in a variety of applications including the softening/texture modification of substrates such as paper, textiles, human skin surfaces and hair tresses, as well as in applications for metal working, and lubrication.
Amphoteric compositions of various types including derivatives of polyamines are known and have been used over the years for a variety of applications including surfactants in detergent and dishwashing formulations, fabric and paper treating compositions, metal treating and corrosion inhibition, and the like. For example, U.S. Pat. No. 2,999,069 to Masci teaches detergent compositions containing amnphoteric derivatives of amidoamines but does not teach or disclose diamide or polyamide compositions having a reactive secondary, internal nitrogen amine site which is carboxyalkylated as provided in the present invention. Liquid dishwashing compositions disclosed in European Patent Application No. 92 203 230.5 to Jadwiga Palicka include amphoteric surface active agents; however, neither diamide nor polyamide compositions having a secondary, internal nitrogen amine site which is carboxyalkylated are disclosed by Palicka. U.S. Pat. No. 5,322,630 to Williams et al. discloses amphoteric derivatives of a broad range of fatty polyamines, fatty amidoamines, fatty imidazoline amines and polyamines which are employed as oilfield corrosion inhibitors. There is, however, no disclosure or suggestion in the Williams patent of the applications of the amphoteric derivatives of the polyamines herein disclosed, including neither the softening/texture modification of substrates such as paper, textiles, human skin surfaces and hair tresses, nor applications for metal working and lubrication.
Furthermore, providing non-irritating softening agents for fabric or paper substrates, or to human skin or hair, has been a long felt need. Fabrics tend to become slightly harsher after wear and laundering. Moreover, untreated personal hygiene facial tissue paper may be harsh and irritating to inflamed tissues, such as nasal orifice skin.
Various attempts have been made to soften fabrics such as suggested in patents directed to fabric softeners, for example, U.S. Pat. No. 3,904,533 of Neiditch for a liquid fabric softener, and U.S. Pat. No. 4,237,155 of Kardouche and U.S. Pat. No. 5,376,287 of Borcher et al which describe antistatic fabric softener sheets, which include fabric-softening agents, such as cationic and nonionic surfactants.
It is therefore an object of the present invention to define a family of amphoteric compounds comprising derivatives of aliphatic polyamines such as diethylenetriamine and Bis (hexamethylene) triamine wherein the polyamines are first converted to polyamides or imidazoline/amide derivatives thereof
A further object of the present invention is to define and describe a process by which the above described amphoteric derivatives of aliphatic polyamines [ADAPS] may be made.
It is another object of the present invention to provide an effective softener for various substrates such as paper and textile products which might contact human skin, as well as skin and hair substrates themselves.
It is a still further object of the present invention to provide amphoteric surface active agents for use in a variety of other applications, such as metal working, lubricating, etc.
The present invention relates to amphoteric derivatives of aliphatic polyamines [ADAPS] that have important industrial and personal care uses, such as, for example, softeners, lubricants, and conditioners, etc. The ADAPs comprise derivatives of compositions which are intermediate aliphatic polyamides or imidazolines, and preferably aliphatic diamides, derived from aliphatic diamines reacted with more than one substituent moiety selected from the group consisting of long alkyl chain fatty acids, esters and triglycerides, such as derived from animal, vegetable or synthetic sources ranging in molecular distribution from butyric through erucic acids. (e.g. milkfat, soybean oil, rapeseed oil).
The intermediate amide compound is then converted into an amphoteric compound by reacting it with unsaturated carboxylic acids or carboxylated epoxy compounds.
The carboxyalkylation step of the present invention attaches an alkyl carboxylic acid functional group to the secondary internal amine nitrogen atom, thereby forming the amphoteric products of the present invention. The amphoteric product is thus a polyamide or imidazoline derivative of the aliphatic polyamine starting material.
Compounds containing acidic functional groups suitable for use in reacting with aliphatic polyamides in accordance with the present invention include alkyl carboxyl groups i.e., carboxylic acid functional moiety, COOH where the carboxylic acid is derived from one or more unsaturated carboxylic acids or carboxylated epoxy compounds. For the purposes of the present invention such above-mentioned unsaturated carboxylic acids or carboxylated epoxy compounds comprise an amphoteric forming group because the product produced by reacting with one of the acids is an amphoteric product.
Consistent with the above discussion, a first specific group of ADAPs of the present invention may comprise amphoteric derivatives of diethylenetriamine [DETA] wherein the amphoteric derivatives of the present invention are prepared by first reacting DETA as a starting material with at least one member selected from long-alkyl-chain plant, animal or synthetic derived fatty acids, esters and triglycerides, such as, for example, compositions containing substituted or unsubstituted, branched or straight chain, saturated or unsaturated alkyl chain groups ranging in molecular distribution from butyric through erucic acids, that is, containing from 3 to 21 carbon atoms in addition to the carboxyl group.
An intermediate substituted DETA predominately diamide is formed having fatty alkyl moieties of 3 to 21 carbon atoms.
The intermediate amide compound is then converted into an amphoteric compound by reacting it with unsaturated carboxylic acids or carboxylated epoxy compounds.
The carboxyalkylation step of the present invention attaches an alkyl carboxylic acid functional group to the secondary internal amine nitrogen atom, thereby forming the amphoteric products of the present invention. The amphoteric product is thus a polyamide or imidazoline derivative of the aliphatic polyamine starting material.
Amphoteric forming agents suitable for use in reacting with aliphatic polyamides in accordance with the present invention include alkyl carboxyl groups (i.e., carboxylic acid functional moiety, COOH) where the carboxylic acid is derived from one or more unsaturated carboxylic acids, or carboxylated epoxy compounds. Exemplary suitable amphoteric forming agents include vernolic acid, acrylic acid and itaconic acid.
The ADAPS of the present invention also comprise a group of compounds analogous to the above described DETA derivatives, that are amphoteric derivatives of Bis (hexamethylene) triamine. The foregoing discussion applies to such alternative triamines just as it does to DETA.
A third group of products having novel applications is comprised of amphoteric imidazolines which are prepared according to the method hereinafter described for preparation of the DETA derivatives.
The following general structural formulas numbers 1 through 2 comprise the novel compounds of the present invention, and are further exemplified and represented in Table 1 below.
Formula 1, below, generically shows diethylenetriamine [DETA] amphoteric derivatives more particularly set forth in Table 1 below. Formula 1 is a diamide, having an amide group at each end of the molecule. The central (secondary) nitrogen site on the molecule is further reacted to form the amphoteric end product of the present invention.

wherein:
R1 is a saturated or unsaturated aliphatic mono or poly carboxylic acid moiety having one more carboxyl functional groups derived from intermediates containing olefinic or epoxy reactive sites, and may have one or more branched saturated or unsaturated, substituted or unsubstituted aliphatic chains containing from 2 to 18 carbon atoms;
R2 and R3, which may be the same or different, can be a straight or branched, saturated or unsaturated, substituted or unsubstituted alkyl chain of 3 to 21 carbon atoms; and
x is an integer of 1 to 5.
Formula 2, below is a generic DETA-derived imidazoline, where the acidic functional group making the molecule amphoteric is attached to the quaternary nitrogen. Formula 2 is more particularly set forth in Table 1 below. 
wherein:
R1 is a saturated or unsaturated aliphatic mono or poly carboxylic acid moiety having one or more carboxyl functional groups derived from intermediates containing olefinic or epoxy reactive sites, and may have one or more straight or branched, saturated or unsaturated, substituted or unsubstituted aliphatic chains containing from 2 to 18 carbon atoms; and
R2 and R3, which may be the same or different, can be a straight or branched, saturated or unsaturated, substituted or unsubstituted alkyl chain of 3 to 21 carbon atoms.
The diamide and imidazoline-amide intermediate compositions suitable for use in the preparation of amphoteric compositions of the present invention in accordance with the practice of the invention are well known and include those derived from substituted or unsubstituted, branched or straight chain, saturated or unsaturated fatty acids, esters, or triglycerides with fatty alkyl amide moieties containing from 4 to 22 carbon atoms. Examples of suitable fatty acids, esters or triglycerides include octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, methyl esters or glyceride esters of such acids or mixtures thereof as are found in coconut oil, palm oil, sunflower oil, soybean oil, rapeseed oil, castor oil, fish oil, tallow fat, milk fat, lard and other natural sources or may be of synthetic origin.
The materials of the present invention are embodied in reactions carried out under the following conditions, as noted in the Examples below.
For example, amphoterics are derived from DETA-diamides, such as shown in Example 1 below, wherein linoleic-DETA diamide monopropionate is produced, from a two-step reaction wherein soybean oil and diethylenetriamine are first reacted, followed by a second reaction wherein acrylic acid is added.
In Example 2 below, oleic DETA diamide is produced by reaction of a mixture of olive oil and diethylenetriamine.
In Example 3 below, to the amide of example 2 there is added acrylic acid, to produce oleic DETA diamide monopropionate, or, as noted in Example 4 below, there is added itaconic acid, to produce oleic DETA diamide mono-3-carboxybutyrate.
As noted in Example 5 below, caprylic-capric-DETA diamide propionate is produced from the reaction of a mixture of caprylic-capric triglyceride and diethylenetriamine, which is further reacted with acrylic acid.
Furthermore, as noted in Example 6 below, dioleyl-imidazoline-amide-propionate is produced from two reactions, namely a reaction of a mixture of oleic acid and diethylenetriamine, which is further reacted with glacial acrylic acid.
The foregoing present invention includes aliphatic intermediate derivatives of polyamine compounds which result in amphoteric imidazolines or preferably diamides having a carboxyalkylated internal amine nitrogen site. Carboxyalkylation is achieved by reacting, as indicated hereinabove, a substituted triamine or diamide intermediate with an amphoteric-forming group consisting of unsaturated carboxylic acids or suitable carboxylated epoxy compounds.
The resulting compounds are useful as softeners for paper, tissues, fabrics, hair and skin, and a novel method of softening is disclosed based on the use of the compounds described herein. Because the novel compounds of the present invention provide antiwear properties, a method of using these compounds of the present invention in metal working is also taught.
It is therefore a further aspect of the invention to use the amphoteric derivative compositions of the invention, for example, as softening agents for paper such as facial tissue paper, textiles, hair and human skin in amounts of 0.1 to 10% by weight and for metal working applications such as lubricating and antiwear compositions in amounts of from about 0.1% by weight.